In a substrate processing apparatus according to the related art, the temperature of each of regions of a process furnace is measured. When, for example, components of a reaction furnace of the substrate processing apparatus are replaced with new components, a temperature-flat zone in the process furnace changes. Thus, a method of compensating for a change in temperature of the inside of the process furnace by measuring the inside temperature of the process furnace is performed. The method of compensating for a change in temperature of the inside of the process furnace by measuring the inside temperature of the process furnace may also be performed when, for example, the substrate processing apparatus is first driven. When the method of compensating for a change in temperature of the inside of the process furnace is performed, the following work is conventionally performed. First, an operator individually prepares a temperature measurement lifting fixture (auto-profiler), attaches a temperature measuring device to a vertical (upward/downward) movement unit of the fixture, accesses a data logger (electronic measuring machine) and a personal computer, and obtains temperature data regarding a heater temperature-flat zone of a process furnace when the inside temperature of the process furnace is increased. The operator calculates a temperature correction value based on the temperature data. However, the operator has to individually prepare the auto-profiler each time, thereby increasing costs and lowering workability. Also, even if a temperature correction value is calculated using the same device, the temperature correction value may vary according to an operator's skill and thus the performance or quality of a product is not uniform. Thus, research has been conducted on a method of obtaining temperature data regarding a heater temperature-flat zone in a process furnace without using the auto-profiler (see, for example, Japanese Unexamined Patent Application Publication No. H9-5172 (JP Application '5172)).
Although JP Application '5172 discloses measuring a temperature-flat length of a heater using a transfer device instead of a fixture such as an auto-profiler, a method of attaching a temperature measuring device (thermocouple) to the transfer device or a method of setting the temperature measuring device (thermocouple) at a measurement start position is not actually disclosed in JP Application '5172. According to JP Application '5172, variations occur when individual operators set the temperature measuring device at the measurement start position and workability varies according to the operators' skill. Thus, a variation occurs in a point at which a temperature-flat length of a heater is measured according to operators' skills, and thus the reliability of temperature control performance or the quality of a substrate is eventually likely to be lowered.